本项目我们通过分析北半球87个无线电探空站点从1998年至2017年以来20年的数据，SABER/TIMED卫星2002年以来以及COSMIC卫星2006年以来的温度观测资料，并结合再分析资料和局地的遥感设备观测数据，研究从近地面直到低热层高度大气重力波活动的长期变化。由此揭示全球不同纬度、高度和季节重力波活动对太阳活动11年周期的响应和长期变化趋势，探寻这一响应和长期变化的形成机制。并通过与背景大气温度和风场长期变化的定量比较，研究重力波活动在气候学尺度上与背景大气的相互作用机制。该项目的研究对于我们理解重力波对中高层大气的气候学效应以及中高层大气的气候学变化都有重要意义。

In this project, we are going to study the long term variation of gravity wave activity from the near ground height up to the lower thermosphere by analyzing the 20-year radiosonde data in 1998-2017 from 87 stations in the Northern Hemisphere, temperature data from SABER/TIMED since 2002 and from COSMIC since 2006, MERRY and ECMWF reanalysis data, and local wind and temperature data from ground-based observations. We will focus on the latitude, height and season dependent response to the 11-year solar cycle and linear trend of the gravity wave as well as the mechanisms accounting for the response and linear trend. In addition, we plan to investigate the interaction between gravity waves and the background atmosphere they propagating in on the climatological time scale by comparing the long term variations of the gravity wave and the background wind and temperature. We believe that this research is helpful to further understanding the climatology of the middle and upper atmosphere by elucidating the climatological impact of gravity waves on the middle and upper atmosphere.